This invention relates to a machine for filling containers such as bottles with a liquid.
Bottle filling machines may be comprised of an annular tank or bowl which contains the liquid with which the bottles are to be filled. Several filler valves are mounted to the bowl and they are arranged to pass over conveyed bottles. The bowl is mounted on a platform or table which rotates in a horizontal plane about a vertical axis that is coaxial with the annular ring bowl. There may be vertical lead screws or other lifting devices mounted on the platform which runs on a circular track on which the bowl rotates The lead screws or other form of lifting and lowering devices are activated to change the height of the bowl and the filler valves mounted thereto when the machine must be adapted for filling bottles of various heights. When the height of the bowl and the filler valves carried on it is changed, the valve operating devices and cam tracks and the like, which are usually arranged concentrically to the bowl, must also undergo a change in height It is desirable to be able to convert the machine for switching from one container or bottle size to another as rapidly as possible and to minimize the number of machine components that must be adjusted individually. It is also important that components which rotate with the bowl maintain the proper angular relationship with respect to machine components arranged adjacent the bowl. In one known type of filling machine, a rotor which supports filler valve operating devices and a carrier support for other control components, is adjustable in height on stationary columns and is fixed in place by means of clamping devices which must be individually actuated manually. The rotor and carrier support are capable of being connected with each other with pronged couplings for the purpose of adjusting all components uniformly.
Accomplishing positive interlocking between the carrier supports and rotor and release of the couplings for freeing the rotor for continuing filling operations, requires a series of manual disassembly and reassembly operations which are time consuming and hazardous in a sense because the machine attendants must get up to the highest point of the machine to make certain changes.
In German Patent DE-AS No. 2,100,284, a container filling machine is shown wherein control elements for the filling valves are moved vertically by means of a height adjustable holder which is arranged on vertical supports for locating all the machine components involved in filling at a height appropriate to the height of the containers being filled. In the patented machine, there is a mechanically actuatable height adjustment which has separate drives for, on the one hand, the upper part of the machine with the bowl and filling valves and on the other hand, for the mount of the support devices for the carrier of the control elements for the filler valves. The supports for the mount of the height adjustment are each individually provided with lead screws and parts of a gearing unit are connected to each other by an intermediate shaft. The gear units are driven by a motor which operates various drive chains having different speeds. The low rpm drive chain thereby either acts on the mount by means of the supports or acts on the upper part of the machine by means of the carrier columns. Thus, a guiding drive with one of the height adjustable parts of the machine is formed while the high rpm drive chain which is in contact with the other height adjustable part of the machine constitutes a follow-up drive. This arrangement is extremely complex, technical and costly. Furthermore, the follow-up control permits a certain amount of freeplay or dislocation, as a result of which there is a lack of certainty as to the relationship between the filling valve carrying bowl on the rotor and the carrier support for the control components.
German Offenlegungsschrift DE-OS No. 3,241,435 shows another arrangement for obtaining height adjustment in a filling machine. In this laid open application, control is accomplished by means of a carrier support provided with a height adjusting device for achieving height positioning of various machine components. In this arrangement, a positioning drive associated with the height adjustment device is capable of being switched on for an appropriate length of time, and after achieving the desired vertical elevation, can be switched off again. Particularly, the positioning drive for the carrier support should be capable of switching on and off in response to signals such that the positioning drive functions under the influence of a motor having a brake and the electrical circuit components are based on digital technology.
The height adjustment device referred to in the preceding paragraph is basically a type having a worm gear, an endless screw, and a gear and threaded spindle connected with a drive motor and its gear reduction device. The power transferred by means of a chain to the height adjustment device and its telescopic arrangement with an arm extending to the bowl furthermore makes the arrangement and the procedure particularly complex and problematical.
Still another existing container filling machine has the carrier support for the control components supported by means of several holders situated on stationary columns and movable in height as in German Gebrauchsmuster DE-GM No. 85 11 614. Each clamp or holder has an L-shaped clamping arm which can be opened or closed by means a pneumatic cylinder and there is a swivelable interlock which is operated by a second pneumatic cylinder and can enter into a dog-like component arranged on the filling machine bowl. This type of filling machine is costly to construct and requires a complicated control system for both groups of pneumatic cylinders. This is because there must be assurance that all interlocks are engaged before the clamping installation can be released in order to avoid an unwanted dropping of the parts with the carrier support. Conversely, all clamping devices must first be closed before the interlocks can be disengaged. Any height adjustment requires a high degree of attention and concentration on the part of service personnel.